Wii U Network IDs can be transfered to a new console by Nintendo
Nintendo of America has tired to clear up a bit of confusion surrounding the transfer of online IDs for Wii U consoles owners. According to NOA, while Wii U users are unable to transfer Network IDs between consoles, or even sign-in on a different console, the use of Network IDs on "other devices" will be possible "in the future." Should your Wii U break or sprout legs and go on a city destroying rampage - no worries: just wrangle the unruly system, toss it in a box, and send it off to Nintendo - not the retailer you purchased it from.
"Nintendo of America's repair process includes the transferring of the Nintendo Network ID to a new Wii U console if a replacement system is needed," an NOA rep told Kotaku.